Hydrogen economy from the viewpoint of nonferrous extractive metallurgy

Abstract

Uncertainties in the worldwide supply and economics of petroleum-based fuels prompt a consideration of hydrogen as reactant and fuel for metallurgical processes.E NGINEERS concerned with the technology and economics of metal extraction are acute!y aware of two factors which are working to bring about major changes in this large industry: energy and pollution contro!. The present paper will, through the subject ofhydrogen economy, show one path which may be taken in the future to counteract these factors while at the same time provide intrinsic technical and economic benefits. Weshali first briefly consider the question of primary energy, since this is of direct and immediate concern to all extractive metallurgical processes.The historie usage of fue! for metallurgical processes has evolved from carbon, as charcoal, through coal, coke and finally to oil and natural gas. Nuclear energy presents a probable alternative but not on a wide scale, at least for the immediate future.Looking to the future of petroleum, which will remain a major primary energy source for some years, we see growing apprehension over supply. Enormous worldwide consumption is rapidly depleting resources. Moreover, political and military factors render uncertain even those resources which remain. As a result, modern petroleum-dependent economies seem to be shifting to an age of synthesis of an extremely large amount of energy.With regard to the problem of environmental pollution, we in]apan are well aware that the rapidly increasing amounts of industrial wastes, particularly those from fossil fuels, have reached the limit of the cleansing ability of nature. This has forced a change in the customary concept of values which, in the past, always gave preference to economics.The two factors, energy availability and environment, have led to two corresponding technological thrusts. The first is the obvious development of new fossil fuel resources. The second, in many ways related to the first, is the improvement of pollution control techniques and, at the same time, a tendency to change to ever cleaner energy sources.The above discussion concerns chiefly the primary energy sources which, as we have no ted, will tend to shift from fossil fuel to nuclear fuel over the intermediate future. Secondary energy sources must also, however, be considered. This is especially true in and for the process metallurgie al industry, and it is at this point that we wish to open our consideration of hydrogen.Many general remarks 1 • 4 have already been published regarding the viability of hydrogen as a secondary energy source. From these, we can list the following properties of hydrogen viewed as a fuel:1) It exists in indefinite supply in the form of water. 2) It produces negligible pollutants on combustion. 3) Its use does not disturb the cyclic system of nature. 4) As an energy carrier, its storage and transportation properties are both superior to electric power.6-JOM, DECEMBER 1975